- the maximum operating capability of a system (especially an aircraft)
"test pilots try to push the envelope"
- a natural covering (as by a fluid)
"the spacecraft detected an envelope of gas around the comet"
- a curve that is tangent to each of a family of curves
- Tom sealed the envelope.
- I need an envelope.
- Tom slit open the envelope.
- Tom is pushing the envelope.
- I handed Tom the envelope.
- Tom ripped open the envelope.
- I already have an envelope.
- Do you need an envelope?
- Please give me an envelope.
- He cut the envelope open.
- He ripped the envelope open.
- I ripped the envelope open.
- I addressed the envelope containing the invitation.
- An envelope and a stamp, please.
- Stick another stamp on the envelope.